2023/2024 HD I/M & Truck and Bus Regulations
On-Road Heavy-Duty Diesel Vehicles (In-Use) Regulation and Heavy-Duty Inspection and Maintenance (HD I/M) Regulation
Diesel trucks and buses with a GVWR that is 14,001+lbs must reduce exhaust emissions by meeting particulate matter (PM) filter requirements by upgrading your vehicle to 2010 engine model year or newer engine using diesel exhaust fluid (DEF) or other CARB approved engine.
The Regulation applies to:
- Diesel vehicles with a gross vehicles weight rating greater than 14,000lbs.
- Privately and federally owned trucks and buses that operate in California
- Any person, business, school district, tribal reservation, or federal government agency that owns, operates, leases or rents affected vehicles.
Low mileage limits for 2024 compliance year is 1000 miles in the state of California. Out of state miles and emergency operation miles are exempt for the mileage limit. Vehicle must be registered with CARB to qualify for low mileage exemption. MUST file odometer reading on TRUCRS web site before January 31st of each year.
New for 2024 – CLEAN TRUCK CHECK (CTC)
